This incident at Quorn on the Great Central Railway has generated a lot of comment amongst UK railfans and the current (uninformed i.e. not official) opinion seems to be that blame might end up being divided between the signalman and the crew.
Nicole is right in saying that the trap point is rodded to the box; however, the fact that the driver sounds the whilstle is a standard response to an instruction/permission to move his train, so perhaps the interlocking with the signal failed.
Did the crew keep a proper lookout? well, not apparently, but we only see one angle and one segment of the event .... similarly, there are no hand or flag signals form the signal box and the man can be seen after the incident giving the whole situation a long stare through the windows of his door, so clearly he was surprised too.
All I can say is that events like this happen very very rarely in real life but very often on my O gauge railway, usually when we have visitors to see it happen! - but I don't then have to involve the Rail Accident Investigation Board (RAIB) - someone somewhere is going to be in a lot of trouble here on a Railway that has always been very efficient and professional in the way it is run.
As a footnote - Sir Topham Hatt - are U.S. railfans aware that originally he was (and still is in the UK) called the Fat Controller - but that (it is said) his name was altered for the U.S. so as not to upset anyone ......?
regards
David